Wall plug-in time switch

ABSTRACT

A wall plug-in time switch wherein a pair of shouldered wall prongs are uniquely mounted in a housing of the time switch for connecting the time switch to a conventional wall mounted outlet box. The construction includes shoulders on the wall prongs which are sandwiched between bosses which are formed on a rear casing and a front cover of the time switch housing. Terminals for an electrical motor are also located in the vicinity of the wall prongs so that the wall prongs, and electric motor are reliably connected to each other and positioned within the housing with the use of relatively few parts.

United States Patent 11 1 Balchunas 1 1 July 16, 1974 WALL PLUG-IN TIMESWITCH 3,728,500 4/1973 Ingram 200/38 FB [75] Inventor: fillzgrs'les A.Balchunas, Hopkinton, Primary Examiner George Harris Attorney, Agent,orFirm--Leonard J. Platt; John F. [73] Assignee: General Electric Company,Cullen; George R. Powers Bridgeport, Conn.

22 Filed: Feb. 13, 1973 [571 AB STRACT [211 App]. NO'I 331,763 A wallplug-1n t1me switch wherein a pair of shoul- Related US. ApplicationData Division of Ser. No. 260,759, June 8, l972, Pat. No. 3,754,107.

v References Cited UNITED STATES PATENTS 3/1954 Kountz ZOO/38A .6/l97lBanathy 200/6 BB dered wall prongs are uniquely mounted in a housing ofthe time switch for connecting the time switch to a conventional wallmounted outlet box. The construction includes shoulders on the wallprongs which are sandwiched between bosses which are formed on a .r teasn n a tc vs f etimesw t h housling. Terminals for an electrical motorare also located lin the vicinity of the wall prongs so that the walllprongs. and electric motor are reliably connected to ,each other andpositioned within the housing with the use of relatively few parts. I MI i 1 Claim, 6 Drawing Figures L LUQ-INIIME SWIIQH W This is a division,of application Serial No. 260,759, filed June 8, 1972 now US. Pat. No.3,754,107, dated Aug. 21, 1973.

BACKGROUND OF THE INVENTION This invention relates to a wall plug-intimer, and more sv r as. inn sysisons ruc r mounting and housing theinlet prongs. electric motor and other P PBP .Qf .ay el ..-.P P :in timr- With a conventional wall plug-in timer a plastic housing is usuallyprovided for enclosing an electric motor for driving a 24-hour timewheel which is rotatably mounted at the front of the housing. A pair ofinlet prongs extend rearwardly from the housing for connecting the timeswitch to a conventional electrical outlet box, and a pair of receptacleslots are usually formed in the front portion of the housing forpermitting a device to be controlled, such as an electric coffeemaker orlamp, to be plugged into the receptacle slots. Naturally, contactsprings are positioned immediately below the receptacle slots for makingappropriate contact with the electrical plug of the Coffeemaker or lampto be controlled. Such timers also conventionally include electricalwiring between the inlet prongs, the electric motor, switch contacts,and the electric outlet receptacle contacts. My invention is concernedwith such a wall plug-in timer,-and more particularly to a uniquearrangement for locating and mounting the inlet prongs, receptaclespring contacts, and the electric motor with the use of relatively fewparts which may be readily and reliably connected to each other.

SUMMARY or ruemvenr ou 7 Accordingly, it is a primary object of thisinvention to provide an improved wall plug-in timer which may beinexpensively manufactured with the use of relatively few parts. 7

In accordance with one of the aspects of this invention a rear casing ofthe timer is formed with an inwardly projecting boss which is formed ofplastic or other suitable electrical insulating material. A pair ofslots are formed in the boss and a pair of shouldered inlet prongs areinserted within the slots. The shoulders on the inlet prongs extendoutwardly away from each other and are positioned against an innersurface of the boss. Terminal portions of the inlet prongs extendinwardly away from the surface of the boss. A complementary boss isformed on a front cover of the time switch housing for sandwiching theshoulders of the inlet prongs between the boss on the rear casing andthe boss on the front cover. The terminal portions of the inlet prongsare positioned on opposite sides of the boss which is formed on thefront cover and connec* tions to an electric motor may be readily madeto these integrally formed terminals of the inlet prongs without the useof separate wires. With this construction. the inlet prongs are securelyheld in a time switch housing. and an electric motor may be readily connected to the inlet prongs. Thus. a very simple yet effective andreliable construction for a wall plug-in timer haahsenaqhie sdt 2 BRIEFDESCRIPTION oF THE DRAWING I I Other objects and attendant advantages ofthe invention will be apparent from the following description taken inconnection with the accompanying drawing in which:

FIG. 1 is a front elevational view of a time switch constructed inaccordance with my invention;

FIG. 2 is a front elevational view of the time switch illustrated inFIG. 1 with a front cover of the time switch removed for purposes ofillustration;

FIG. 3 is a cross-sectional view of the time switch illustrated in FIG.1 taken along the line 33 of FIG. 2;

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing andfirst particularly to FIGS. 1 and 2, there is shown a wall mounted timeswitch constructed in accordance with my invention. The time switchincludes a pair of switch contacts 10 and 12 for controlling theoperation of an electric coffeemaker, lamp, or similar appliance, and asynchronous electric motor 14 is provided for operating the switchcontacts 10 and 12 at the preset times. As illustrated more particularlyin FIGS. 2 and 3, the motor 14 drives a gear reduction unit 16 which inturn rotates a shaft 18.

With particular reference to FIGS. 1 and 3, the shaft 18 carries a24-hour dial 20 which carries ON and OFF trip levers 22 and 24,respectively. The positions of the ON and OFF trip levers on the 24-hourdial 20 may be manually set by a user of the time switch to turn anappliance on and off at the desired-times, and thus, the dial 20 drivesthe trip levers 22 and 24, and at the appropriate times the trip leversactuate a switch operating mechanism 26 to open and close the switchcontacts 10 and 12 at the preset times.

In carrying out the object of my invention the entire rear casing of thetime switch is made from a single molded member 28 which includes a rearpanel 30 and forwardly extending side wall portions 32 and 36, a topwall 38 and a bottom wall 34. Forwardly extending studs 39 are alsointegrally formed with the rear casing for mounting the electric motor14, the reduction gearing 16, and the other components of the timeswitch.

In accordance with my invention a pair of shouldered inlet prongs 40 and42 are uniquely formed and located with respect to a pair of outletreceptacle springs 44 and 46 and the electric motor 14 for enablingthese parts to be effectively and reliably connected to each other withthe use of relatively few parts. To achieve this the outlet receptaclesprings 44 and 46 which are provided for making contact with a plug ofthe appliance to be controlled are positioned just forwardly of theinlet prongs 40 and 42 which are arranged to be plugged into anyconventional wall mounted outlet box. The conventional synchronouselectric motor 14 includes an electrical coil 48 which surrounds theusual field laminations 50 for driving a rotor which is positionedwithin a casing portion 52. conventionally,

input electrical terminals 54 and 56 are positioned at opposite sides ofthe motor coil 48, and thus, as shown, the motor coil terminals 54 and56 are located closely adjacent to a respective inlet prong 40 or 42 anda re- .spective outlet receptacle spring 44 or 46.-

As shown more particularly in FIG. 5, a rivet 58, a stamped sheet metalpiece 60 and a piece of solder 62 is all that is required for connectingthe inlet prong 42 to the outlet receptacle spring contact 46 and one ofthe motor terminals 56. As shown, the rivet 58 extends through an innerforwardly extending terminal portion 64 of inlet prong 42, a forwardportion of a sheet metal connector 60 and an outer portion 66 of thereceptacle spring contact 46. An aperture 68 is formed in the terminal56 of the motor coil and a reduced portion 70 of the sheet metalterminal 60 extends through the aperture and is held therein by a dropof solder 62. A generally similar arrangementis provided for connectingthe inlet prong 40 to the other terminal 54 of the motor coil 48, and asillustrated in FIG. 5, a rivet 72 extends through the inlet prong 40 anda sheet metal strip 74. The connection is completed by attaching thestrip 74 to terminal 54.

With the construction thus far described, most of the componentsillustrated in FIG. including the electric motor 14, inlet prongs 40 and42, and the receptacle spring contact 46 may be readily connected andsubassembled to each other and held generally in the positionillustrated in FIG. 5. A unique simple arrangement is provided forrigidly holding these parts in their assembled position within the timeswitch casing. As shown more particularly in N64, a forwardly extendingboss 82 is-integrally formed with'the rear panel 30 and is'provided withtwo through slots 84 and 86 for receiving the inlet prongs 40 and 42. Asshown, the inlet prongs 40 and,42 are provided with outwardly extendingshoulders 88 and 90 for abutting a forward surface 92 of the boss andalso for spacing the forwardly extending terminal portions 64 and 65 ofthe inlet prongs outwardly away from the end portions 94 and 96 of thereceptacle springs 44 and 46, respectively, so as to leave sufficientroom for the inlet prongs of an appliance inlet plug which may beconnected to the receptacle spring contacts 44 and 46. 1

A front cover 100 of the time switch housing is also integrally formedof molded plastic material and is provid ed with parts that arecomplementary to the parts of the rear casing for mounting the electricmotor 14, the

reduction gearing 16, the inlet prongs 40 and 42, and the other parts ofmy unique time switch. As illustrated more particularly in FIGS. 3 and4, the front cover includes a front panel portion 102 for supporting ashaft 18, and the 24-hour dial 20. Two integrally formed slots 104 and106 are positioned immediately above their respective receptacle springcontacts 44 and 46.

Rearwardly extending wall portions 108, 110, 112 and 114 of the frontcover are arranged to be complementary with the forwardly extending wallportions 32, 34, 36 and 38 of the rear casing.

The front cover 100 also includes a rearwardly extending enlarged boss116 which is positioned opposite to the forwardly extending boss 82 ofthe rear casing. With this arrangement, as shown more particularly inFIG. 4, a spacer member 118 formed of suitable electri- 4 cal insulatingmaterial is sandwiched between the rear-. wardly extending boss 116 andthe shoulders 88 and 90 of the inlet prongs for securely holding theinlet prongs 40 and 42 in their assembled positions. As shown, a 5 screw120 or other suitable connecting means may be readily inserted throughan aperture 122 formed in the forwardly extending boss 82 through anaperture 124 formed in the insulating member 118 and into the rearwardlyextending boss 116. Thus, the parts are securely held to each other intheir desired operating relationship, and the prongs 40 and 42 cannot beinadvertently pushed further into the housing when they are insertedinto a wall outlet.

From the foregoing description it can be appreciated that the parts maybe readily connected to each other by first constructing the subassemblyillustrated in FIG. 5 and then sliding the inlet prongs 40 and 42outwardly through their respective slots 84 and 86 which are formed inthe rear casing. During this insertion apertures 150 and 152 which maybe formed inthe motor field laminations are aligned with apertures whichare formed in the rear casing spacer posts 154, and an output pinion 156of the motor may be inserted within its plastic guide 158 which isintegrally formed with the rear casing of the time switch. Suitablescrews 160 and 162 may be provided for attaching the motor fieldlaminations and the motor to the rear casing of the time switch. 1

The next convenient step in the assembly of the time switch is to placethe receptacle spring 44 and its switch blade 78 on the steps 132 and134 which are integrally formed with the rear casing. The assembly maybe readily completed by placing the front cover over rear casing, andcarefully positioning the rearwardly extending boss 116 betweenreceptacle springs 44 and 46.

Then a screw 120 may be inserted through the aperture 122 formed in therear casing boss '82 and threaded into the boss 116 which is formed onthe front cover. Additional screws may be inserted in the apertures 168and .170 which are formed at the lower corners of the rear casing of thetime switch.

From the foregoing discussion, it can be appreciated tha my unique inlett99-39 s estriq i tq lne rs readily assembled andreliably housed withina time switch with the use of relatively few parts. All internal wiringwhich is usually found in conventional time switches has beeneliminated. Thus, an exceedingly simply yet reliable electric timeswitch construction has e n achieved, W1

.what claimis m.

1. A wall plug-in timer mechanism comprising:

a. a housing formed of electric insulating material including a rearcasing and a front cover;

b. a forwardly extending boss formed in said rear casing having an innerfront surface and a pair of slots extending therethrough;

c. a pair of shouldered inlet prongs extending rearwardly through saidslots and protruding rearwardly from said housing, the shoulders on saidinlet prongs being in abutting relationship with the inner front surfaceof said boss;

d. a complementary boss formed in said front cover and being providedwith a spacer member having a rear surface for sandwiching the shouldersof said inlet prongs between the bosses formed on said rear casing andsaid front cover for securely holding said inlet prongs on said housing;one of the inlet prongs and the other motor coil tere. an electric motorpositioned in said housing, said minal being directly connected to theother inlet motor including a coil having a pair of terminals 10- prong.cated adjacent to said inlet prongs, one of said motor coil terminalsbeing directly connected to 5

1. A wall plug-in timer mechanism comprising: a. a housing formed ofelectric insulating material including a rear casing and a front cover;b. a forwardly extending boss formed in said rear casing having an innerfront surface and a pair of slots extending therethrough; c. a pair ofshouldered inlet prongs extending rearwardly through said slots andprotruding rearwardly from said housing, the shoulders on said inletprongs being in abutting relationship with the inner front surface ofsaid boss; d. a complementary boss formed in said front cover and beingprovided with a spacer member having a rear surface for sandwiching theshoulders of said inlet prongs between the bosses formed on said rearcasing and said front cover for securely holding said inlet prongs onsaid housing; e. an electric motor positioned in said housing, saidmotor including a coil having a pair of terminals located adjacent tosaid inlet prongs, one of said motor coil terminals being directlyconnected to one of the inlet prongs and the other motor coil terminalbeing directly connected to the other inlet prong.